<div class="col-md-3">
  <div class="affix" role="complementary">
    <ul class="nav nav-pills nav-stacked">
      <li><a href="#whatis">What is SLOW?</a></li>
      <li><a href="#Install">Install</a></li>
      <li><a href="#GettingStart">Getting Start</a></li>
    </ul>
  </div>
</div>